Surface mount lateral light emitting apparatus and fabrication method thereof

ABSTRACT

A surface mount lateral light emitting apparatus, which includes a light emitting device; a first lead frame connected to the light emitting device; a second lead frame connected to the light emitting device; a first resin molding body in which a concave portion for mounting the light emitting device is formed and the first lead frame and the second lead frame are fixed; and a second resin molding body which covers the light emitting device to form a light emitting surface in the concave portion of the first resin molding body, wherein the first resin molding body contains a filler or a light diffusion agent; wherein in a periphery of the concave portion, a width of at least one side of the first resin molding body is not more than 0.2 mm; and wherein the first resin molding body and the second resin molding body are formed with a thermosetting resin.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the foreign priority benefit under Title 35,United States Code, §119(a)-(d) of Japanese Patent Application No.2006-355092, filed on Dec. 28, 2006, the contents of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a surface mount lateral light emittingapparatus (side-view type light emitting apparatus) which is used for,for example, a lighting apparatus, a display, a backlight of a cellularphone, a video auxiliary light source, and other general consumer lightsources, and a fabrication method of the surface mount lateral lightemitting apparatus.

2. Description of Related Art

A surface mount lateral light emitting apparatus which usually uses, forexample, a light emitting diode (LED) is small and excellent in powerefficiency, and emits a brilliant color. In addition, since the lightemitting device is a semiconductor device, there is no concern about ablowout of the device. Further, the light emitting device is excellentin an initial drive performance and robust against vibrations and repeatof ON and OFF of the device. Since the light emitting device has theexcellent characteristics described above, a light emitting apparatususing a light emitting device such as a LED and a laser diode (LD) hasbeen utilized as various kinds of light sources.

The surface mount lateral light emitting apparatus includes a lightemitting device, a mounting lead frame for mounting the light emittingdevice, a connecting lead frame to be connected to the light emittingdevice through a lead wire, a resin molding body (first resin moldingbody) covering most of each lead frame, and a translucent encapsulationresin (second resin molding body) for covering the light emittingdevice. This is disclosed in, for example, Japanese Patent Laid-openPublication No. 2005-259972. A concave housing portion is disposed on alight emitting surface formed on the first resin molding body, and thelight emitting device is mounted on the mounting lead frame arranged inthe concave housing portion. A translucent encapsulation resin, in whicha fluorescent material is dispersed, is filled in the concave housingportion after an electrode of the light emitting device is connected tothe connecting lead frame through the lead wire.

There are two types of surface mount light emitting apparatus, that is,a surface light emitting type (top-view type) and a lateral lightemitting type (side-view type).

A constitution of the side-view type light emitting apparatus isbasically identical to that of the top-view type light emittingapparatus except for arrangements of lead frames. A lead frame which iselectrically connected to the light emitting device and projectedoutside the package is bended so that an end of the lead frame is on aplane identical to the package side face, which is parallel to anoutgoing direction of the light.

It is noted that the side-view type light emitting apparatus is requiredto be ON at all times and has a stable light intensity since theapparatus is used for a backlight of a notebook PC.

Generally, a major molding method of a resin molding body which providesa less expensive high power surface mount light emitting apparatus hasbeen injection molding of a thermoplastic resin because of its highproductivity and thermoplastic property. The side-view type lightemitting apparatus has also been molded by a similar manner. This isdisclosed in, for example, Japanese Patent Laid-open Publication No.H11-45958 (see FIG. 5).

In the side-view type light emitting apparatus, when a width of aperiphery portion of the concave portion is made thinner, a molding ofthe resin molding body by the injection molding using the thermoplasticresin has been difficult due to a low fluidity of the thermoplasticresin. In addition, when a temperature of the molding is increased forimproving the fluidity of the thermoplastic resin, a trouble that a diecan not be released from the resin has happened.

Considering the trouble described above, a technology which uses athermosetting resin instead of the thermoplastic resin for the resinmolding body has been developed. This is disclosed in, for example, theJapanese Patent Laid-open Publication No. 2005-259972.

It is noted that when the resin molding body is mass-produced by theinjection molding, conventionally, the resin is filled and injected in afirst die of a plurality of dies which are arranged in series, and theresin is sequentially filled in the adjacent die. In the resin moldingbody of the side-view type light emitting apparatus, a portion where theresin is filled and injected is the periphery portion of the concaveportion. This is disclosed in, for example, the Japanese PatentLaid-open Publication No. H11-45958.

However, in recent years, a notebook PC is required more reduction insize, weight, and cost. Therefore, a light emitting apparatus to beinstalled in the notebook PC is also required reduction in size, weight,and cost.

In addition, since the die is released from the resin by pushing aportion where the resin is filled and injected after the injectedthermoplastic resin is hardened, the resin molding body is required tohave a strength resistant to the pushing. Therefore, there has been alimitation for thinning a width of the periphery portion of the concaveportion. Specifically, if the width of the periphery portion of theconcave portion is too thinned, a light from a light emitting deviceentirely passes through the periphery portion, thereby resulting inlowering of light extraction efficiency on a light emitting surface. Onthe other hand, if the thin periphery portion of the concave portioncontains too much a light diffusion agent for increasing the lightextraction efficiency on the light emitting surface, a fluidity of thethermoplastic resin forming the thin periphery portion is reduced,thereby resulting in difficulty in molding a thin periphery portion ofthe concave portion.

In addition, even if the thermoplastic resin is merely replaced by athermosetting resin, a molding of the thin periphery portion (afterhardening of the resin) of the concave portion in the side-view typelight emitting apparatus and a molding of a complex shape posed bythinning the apparatus are difficult. Therefore, it has been required toselect, for example, a proper thermoplastic resin and process.

It is, therefore, an object of the present invention to provide a small,light, and less expensive side-view type light emitting apparatus and afabrication method of the apparatus.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provideda side-view type light emitting apparatus, which includes: a lightemitting device; a first lead frame to be electrically connected to thelight emitting device; a second lead frame to be electrically connectedto the light emitting device; a first resin molding body in which aconcave portion for mounting the light emitting device is formed and thefirst lead frame and the second lead frame are fixed; and a second resinmolding body which covers the light emitting device to form a lightemitting surface in the concave portion of the first resin molding body,wherein the first resin molding body contains a filler or a lightdiffusion agent; wherein in a periphery of the concave portion, which isa periphery of the light emitting surface, a width of a straight portionof at least one side of the first resin molding body is not more than0.2 mm; and wherein the first resin molding body and the second resinmolding body are formed with a thermosetting resin.

It is preferable that a thermosetting resin according to the presentinvention is epoxy resin. Especially, the epoxy resin which is reactiveand has no unsaturated bond is preferable, rather than that having theunsaturated bond, such as aromatic epoxy resin, because the epoxy resinhaving the unsaturated bond may be oxidized and a double bond in theresin may be disconnected by irradiation with a light having a shortwavelength and heating, to cause yellow discoloration and degradation.

Epoxy resin containing triazine derivative epoxy resin is furtherpreferable as the epoxy resin of the present invention.

Since the triazine derivative epoxy resin is hardened in a short time, aremaining of unreacted portion due to a shortage of curing agent issuppressed even if a volatile curing agent such as acid anhydride isused. In addition, it is further preferable that the triazine derivativeepoxy resin is solid (for example, powder) at a room temperature beforehardening, thereby assists to disperse a fluorescent material into theresin, and to be transparent after the hardening. In addition, the epoxyresin may be designed as needed depending on the application. Forexample, the epoxy resin may be mixed with a filler and light diffusionagent so that a light emitted from a light emitting device is uniformlyoutput mainly in front and lateral directions. In addition, the epoxyresin may be mixed with white pigments such as barium titanate, titaniumoxide, alumina, and silicon oxide, rather than dark pigments, forreducing absorption of the light. As described above, the epoxy resinmay be mixed with at least one selected from a group of the filler,light diffusion agent, pigment, fluorescent material, reflectivematerial, light shielding material, and light stabilizer, for giving apredetermined function.

With the constitution described above, a resin molding body having athinner periphery of the concave portion can be molded for the side-viewtype light emitting apparatus by using a thermosetting resin having ahigh fluidity.

Therefore, a light emitting apparatus which is excellent in opticalcharacteristics and reliability can be obtained by suppressinginsufficient hardening of the resin and sedimentation of the fluorescentmaterial. Accordingly, the side-view type light emitting apparatus whichis excellent in, for example, heat resistance and light resistance canbe provided.

In addition, the first resin molding body and the second resin moldingbody can be prevented from peeling off at an interface between the firstand the second molding bodies by using a thermosetting resin for boththe first and the second molding bodies.

Since a thermosetting resin has many reactive functional groups on itssurface different from a thermoplastic resin, a strong adhesiveinterface can be formed between the first resin molding body and thesecond resin molding body. Because of the strong adhesion interface, apeeling off at the interface due to thermal expansion and contraction ofthe resin of the second molding body can be prevented even if the secondresin molding body is molded with, for example, silicone resin ormodified silicone resin, which has a large thermal expansioncoefficient.

On the other hand, the gate is arranged in a thick protection wallportion of the periphery, which is a surrounding area of the lightemitting surface 2 as shown in FIG. 1C, of the concave portion 40 c.Therefore, an arrangement of the gate and weld line, which are likely tocause a stress cracking, in a thin wall portion such as a thickness of0.2 mm is unnecessary. As a result, the package can be prevented fromcracking even if a thermosetting resin having a large thermal expansioncoefficient repeats thermal expansions and contractions.

In addition, a composition of the thermosetting resin can be easilychanged without losing heat resistance by three dimensional bridgeformations through the hardening. Therefore, a resin molding body forthe side-view type light emitting apparatus which is excellent in lightand heat resistances can be obtained by easily excluding an aromaticcomponent, which has a poor light resistance, by selecting anappropriate composition of the thermosetting resin.

It is preferable that a resin molding body according to the presentinvention is molded by a transfer molding process, which will bedescribed later.

A complex shape which is unable to mold by the injection molding can bemolded by the transfer molding process using a thermosetting resinhaving a high fluidity. Especially, the first resin molding body havingan extremely narrow housing periphery (not more than 0.2 mm) describedabove can be easily molded. Accordingly, the resin molding body which isexcellent in, for example, mass-production, heat resistance, lightresistance, and adhesiveness can be fabricated.

Further, the arrangement of the gate and weld line, which are likely tocause a stress cracking, in the thin wall portion such as the thicknessof 0.2 mm are unnecessary, by arranging the gate in the thick protectionwall portion of the periphery, which is the surrounding area of thelight emitting surface 2 as shown in FIG. 1C, of the concave portion 40c. Therefore, the package can be prevented from cracking even if athermosetting resin which has a large thermal expansion coefficientrepeats thermal expansions and contractions.

In addition, according to a second aspect of the present invention,there is provided a fabrication method of a surface mount lateral lightemitting apparatus, which includes steps of: a first step forsandwiching the first lead frame and the second lead frame by an upperdie having a convex portion corresponding to the concave portion of thefirst resin molding body and a lower die to be used in pairs togetherwith the upper die; a second step for injecting a thermosetting resincontaining a filler or a light diffusion agent into a space between theupper die and the lower die when the upper die is engaged with the lowerdie from a gate disposed on a side face of the first resin molding bodyadjacent to a side face of the concave portion of the first resinmolding body; a third step for heating up the injected thermosettingresin to mold the first resin molding body; a fourth step for mountingthe light emitting device on the first lead frame under the conditionthat at least the upper die is released from the injected thermosettingresin, and for electrically connecting a first electrode of the lightemitting device to the first lead frame and a second electrode of thelight emitting device to the second lead frame; a fifth step for fillingthe thermosetting resin in the concave portion where the light emittingdevice is mounted; and a sixth step for heating up the filledthermosetting resin to mold a second resin molding body.

In the fabrication method of the side-view type light emittingapparatus, the thermosetting resin is injected in a space formed by theupper die and lower die by the transfer molding process from the gatedisposed on the side face of the first resin molding body adjacent tothe side face of the concave portion of the first resin molding bodywhen the upper die is engaged with the lower die. Therefore, a stress isnot applied to the thin periphery portion of the concave portion of thefirst resin molding body when the die is released from the resin, aswell as a good resin flow is achieved. Accordingly, the resin moldingbody which has a thinner periphery portion of the concave portion forthe side-view type light emitting apparatus can be provided.

With the fabrication method described above, the side-view type lightemitting apparatus which is excellent in mass-productivity, molding,heat resistance, and light resistance can be fabricated.

The side-view type light emitting apparatus according to the presentinvention can be reduced in size and weight by thinning a width of theperiphery portion of the concave portion in the resin molding body.Therefore, a less expensive side-view type light emitting apparatus canbe provided by a reduction of resin consumption used for the apparatus.

The triagene derivative epoxy resin, which is a thermosetting resin, isselected in the fabrication method of the side-view type light emittingapparatus according to the present invention. Therefore, the resinmolding body having a thin and complex shape in the periphery of theconcave portion can be fabricated by increasing the fluidity of theresin. Accordingly, the side-view type light emitting apparatus, whichis reduced in size and weight and has a high quality, can be fabricated.

A positional limitation for pressing the resin molding body when the dieis released from the resin has been eliminated by selecting the transfermolding process using a thermosetting resin in the fabrication method ofthe side-view type light emitting apparatus according to the presentinvention. In addition, a resin injection gate of the die is formed in ashape so that the resin flows easily. Therefore, the resin molding bodyhaving the thin and complex shape in the periphery of the concaveportion can be fabricated. Accordingly, the side-view type lightemitting apparatus, which is reduced in size and weight and has a highquality, can be fabricated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view showing a whole side-view type lightemitting apparatus according to an embodiment of the present invention;

FIG. 1B is a front view of the side-view type light emitting apparatusaccording to the embodiment as seen from an opening side of theside-view type light emitting apparatus;

FIG. 1C is a cross sectional view of the side-view type light emittingapparatus according to the embodiment as seen from above of theside-view type light emitting apparatus in FIG. 1B; and

FIGS. 2A, 2B, 2C, 2D, and 2E are cross sectional views showing afabrication process of a side-view type light emitting apparatusaccording to the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, an embodiment of a side-view type light emitting apparatusaccording to the present invention and a fabrication method of theapparatus will be explained by referring to drawings. However, thepresent invention is not limited to the embodiment.

A perspective view of the whole side-view type light emitting apparatusis shown in FIG. 1A. A front view of the side-view type light emittingapparatus as seen from an opening side of the apparatus is shown in FIG.1B. A cross sectional view of the side-view type light emittingapparatus as seen from above of the apparatus shown in FIG. 1B is shownin FIG. 1C.

It is noted that in FIG. 1A and FIG. 1B, for example, a second resinmolding body, which will be described later for explanations, will beomitted.

The side-view type light emitting apparatus according to the embodimentincludes a light emitting device 10, a first resin molding body 40 formounting the light emitting device 10, and a second resin molding body50 for covering the light emitting device 10. The first resin moldingbody 40 is integrally molded with a first lead frame 20 for mounting thelight emitting device 10 and a second lead frame 30 to be electricallyconnected to the light emitting device 10, and forms a portion of apackage.

It is noted that in the explanation hereinafter, a side of the firstresin molding body 40, on which the light emitting device 10 is mounted,is called a light emitting surface 2 or a major face side and theopposite side is called a backside. A side of the first resin moldingbody 40, on which a gate for injecting a resin is disposed, is called aside face (two side faces exist). In addition, one side of the firstresin molding body 40 other than the major face side, the backside, andthe two side faces is called an upper face side and the opposite side iscalled a lower face side.

Hereinafter, each component of the side-view type light emittingapparatus according to the present invention will be explained indetail.

<Light Emitting Device>

The light emitting device 10 includes a pair of positive and negativeelectrodes, that is, a first electrode 11 and a second electrode 12, ona same face side. In the specification, explanations will be made forthe light emitting device 10 which has the pair of positive and negativeelectrodes on the same face side. However, the light emitting device 10which has the positive and negative electrodes on an upper face side anda lower face side, respectively may also be used. In this case, anelectrode on the lower face side of the light emitting device 10 iselectrically connected to the first lead frame 20 using an electricallyconductive die bonding material without using a wire.

The light emitting device 10 is fabricated using a semiconductorstructure which is formed by depositing semiconductors, for example,GaAlN, ZnS, ZnSe, SiC, GaP, GaAlAs, AlN, InN, AlInGaP, InGaN, GaN, andAlInGaN on a substrate as a light emitting layer. A semiconductor devicestructure is a homostructure, or a heterostructure, or a doubleheterostructure which has a MIS junction, or a PIN junction, or a PNjunction. A wavelength of the emitting light may be varied fromultraviolet to infrared depending on a semiconductor layer material anda degree of mixed crystal of the material.

Considering a use of the light emitting device 10 in the field, it ispreferable to use gallium nitride compound semiconductors, which enablea fabrication of a high intensity light emitting device, as thesemiconductor material. In addition, it is preferable to use galliumaluminum arsenides or aluminum indium gallium phosphides for obtaining ared light. However, various kinds of semiconductor materials may be useddepending on the application.

A plurality of the light emitting devices 10 may be used, and a colormixture in a white display can be improved by a combination of the lightemitting devices 10. For example, two green, one blue, and one red lightemitting devices 10 may be combined. It is noted that a wavelength of ared light between 610 nm and 700 nm, that of a green light between 495nm and 565 nm, and that of a blue light between 430 nm and 490 nm arepreferable for applying the lights to a full-color light emittingapparatus of a display.

When a mixed-color light of white colors is emitted using the surfacemount lateral light emitting apparatus according to the presentinvention, it is preferable that a wavelength of a light emitting deviceis not less than 400 nm and not more than 530 nm, and more preferablynot less than 420 nm and not more than 490 nm, by considering, forexample, a complementary color to a light (wavelength) emitted from afluorescent material and a degradation of a translucent resin.

It is still more preferable that the wavelength of the light emittingdevice is not less than 450 nm and not more than 475 nm for improving anexcitation and luminance efficiency of a fluorescent material by thelight emitting device. It is noted that the light emitting device whichhas a principal wavelength in an ultraviolet range less than 400 nm orin a shorter wavelength range of a visible light may be used byutilizing materials which are relatively resistant to ultravioletirradiation.

The light emitting device 10 which has approximately a square shape witha side of 1 mm can be mounted on the surface mount lateral lightemitting apparatus, and the light emitting device 10 with a side of, forexample, 600 μm and 320 μm also can be mounted on the apparatus.

<First Resin Molding Body>

The first resin molding body 40 has a concave portion 40 c whichincludes a bottom face 40 a and a side face 40 b. In the first resinmolding body 40, the light emitting device 10, the first lead frame 20for mounting the light emitting device 10, and the second lead frame 30to be electrically connected to the light emitting device 10 arearranged so that the light emitting device 10 is arranged in the concaveportion 40 c by disposing the first lead frame 20 adjacent to the secondlead frame 30, thereby resulting in formation of a package. A firstinner lead portion 20 a of the first lead frame 20 forms a part of thebottom face 40 a of the concave portion 40 c.

A second inner lead portion 30 a of the second lead frame 30 also formsa part of the bottom face 40 a of the concave portion 40 c, and islocated apart from the first inner lead portion 20 a at a predetermineddistance. The light emitting device 10 is mounted on the first innerlead portion 20 a, which corresponds to the bottom face 40 a of theconcave portion 40 c.

The first inner lead portion 20 a corresponding to the bottom face 40 aof the concave portion 40 c, the second inner lead portion 30 acorresponding to the bottom face 40 a of the concave portion 40 c, afirst outer lead portion 20 b, and a second outer lead portion 30 b areexposed to the outside of the first resin molding body 40. The firstlead frame 20 and second lead frame 30 on the lower side are exposed tothe outside of the first resin molding body 40 and bended to side facesof the body 40, thereby the light emitting device 10 can be electricallyconnected from the side faces of the body 40.

An opening of the concave portion 40 c is tapered to become larger in anopening direction. Therefore, a light extraction in a front direction ofthe apparatus can be increased. Of course, the concave portion 40 c canbe formed without the taper. In addition, even though it is preferablethat a tapered surface is smooth, an irregularity may be formed on thetapered surface for improving adhesion of an interface between the firstresin molding body 40 and the second resin molding body 50. It ispreferable that a taper angle of the opening of the concave portion 40 cis not less than 95 degrees and not more than 150 degrees, and morepreferably not less than 100 degrees and not more than 120 degrees whenthe angle is measured from the bottom face of the concave portion 40 c.

An outer shape of the major face side of the first resin molding body 40is formed in approximately a rectangle in the embodiment. However, theouter shape may also be formed in, for example, an ellipsoid, a circle,a pentagon, and a hexagon. A periphery shape of the major face side ofthe concave portion 40 c is formed in approximately a rectangle in theembodiment. However, the outer periphery shape may also be formed in,for example, an ellipsoid, a rectangle, a pentagon, and a hexagon.

In the first resin molding body 40, a thickness W between a periphery ofthe concave portion 40 c on the major face side and the upper face sideor the lower face side of the first resin molding body 40 is formedextremely thin, that is, not more than 0.2 mm. The width W may also beformed not more than 0.1 mm.

As described above, the major face side of the light emitting apparatushas a small area for forming a housing portion compared with the upperface side (correspond to a housing portion of the light emitting devicein a top-view type light emitting apparatus) of the light emittingapparatus. Therefore, it is necessary that distances between theperiphery of the concave housing portion, which is formed on the frontside, and the upper face side and the lower face side of the lightemitting apparatus are extremely small for securing a larger housingportion.

A material of the first resin molding body 40 is a thermosetting resin.In the embodiment, an epoxy resin containing triazine-derivative epoxyresin is used.

It is noted that the thermosetting resin to be used for the first resinmolding body 40 is not limited to the triazine-derivative epoxy resin.

It is preferable that the first resin molding body 40 is formed by atleast one thermosetting resin selected from a group of an epoxy resin,modified epoxy resin, silicone resin, modified silicone resin, acrylateresin, and urethane resin. Especially, the epoxy resin, modified epoxyresin, silicone resin, and modified silicone resin are preferable.

It is preferable that a hard resin is used for the first resin moldingbody 40 since the first resin molding body 40 has a function of apackage as described above. In addition, it does not matter whether ornot the first resin molding body 40 is translucent. However, the firstresin molding body 40 may be designed as needed depending on theapplication. For example, an amount of light passing through the firstresin molding body 40 may be reduced by mixing the first resin moldingbody 40 with a light shielding material.

On the other hand, the first resin molding body 40 is mixed with afiller and a light diffusion agent so that a light to be emitted fromthe side-view type light emitting apparatus is uniformly output mainlyin a front and a side directions. In addition, the first resin moldingbody 40 may be mixed with white pigments such as barium titanate,titanium oxide, alumina, and silicon oxide, rather than dark pigments,as well as the filler and the light diffusion agent, for reducingabsorption of the light. As described above, the first resin moldingbody 40 may be mixed with at least one selected from a group of thefiller, light diffusion agent, pigment, fluorescent material, reflectivematerial, light shielding material, and light stabilizer, for giving apredetermined function.

<First Lead Frame and Second Lead Frame>

The first lead frame 20 includes the first inner lead portion 20 a andthe first outer lead portion 20 b. The bottom face 40 a of the concaveportion 40 c of the first resin molding body 40 is exposed until thesecond resin molding body 50 is filled in the concave portion 40 c. Thelight emitting device 10 is mounted on the first inner lead portion 20a. An area of the first inner lead portion 20 a is sufficient as long asthe light emitting device 10 can be mounted on the area. However, alarger area is preferable in view of, for example, a thermalconductivity, electrical conductivity, and reflection efficiency of thearea.

The first inner lead portion 20 a is electrically connected to a firstelectrode 11 of the light emitting device 10 through a wire 60. Thefirst outer lead portion 20 b is an exposed portion outside the firstresin molding body 40. The first outer lead portion 20 b is connected toan external electrode and also has a function for conducting a heatgenerated by light emitting.

The second lead frame 30 includes the second inner lead portion 30 a andthe second outer lead portion 30 b. The bottom face 40 a of the concaveportion 40 c of the first resin molding body 40 on the second inner leadportion 30 a is exposed until the second resin molding body 50 is filledin the concave portion 40 c. The second inner lead portion 30 b iselectrically connected to a second electrode 12 of the light emittingdevice 10. An area of the second inner lead portion 30 a is sufficientas long as the second electrode 12 can be connected. However, a largerarea is preferable in view of reflection efficiency of the area.

The first outer lead portion 20 b and the second outer lead portion 30 bare exposed, and the side-view type light emitting apparatus can bemounted by using the outer lead portions 20 b, 30 b. In addition, aninsulator member 90 which is an electrically insulating material may bethinly coated for preventing the first outer lead portion 20 b and thesecond outer lead portion 30 b from being short-circuited by a solderwhen the first electrode 11 and the second electrode 12 are soldered.For example, an insulating resin may be used for the insulator member90.

The first lead frame 20 and the second lead frame 30 may be formed withelectrically conductive materials, for example, iron, phosphor bronze,and copper alloys. In addition, metal plating of, for example, silver,gold, aluminum, and copper may be provided on the surfaces of the firstlead frame 20 and the second lead frame 30 for increasing a reflectionefficiency of a light emitted from the light emitting device 10.

In addition, it is preferable to make the surfaces of the first leadframe 20 and the second lead frame 30 smooth for increasing thereflection efficiency.

In addition, it is preferable that areas of the first lead frame 20 andthe second lead frame 30 are large for increasing heat dissipation. Withthe large areas described above, a temperature rise of the lightemitting device 10 can be effectively suppressed. Therefore, a largercurrent can be supplied to the light emitting device 10.

In addition, it is preferable that the first lead frame 20 and thesecond lead frame 30 are thick for increasing the heat dissipation. Inthis case, the first lead frame 20 and the second lead frame 30 areformed in a predetermined size in a range which does not cause adifficulty in, for example, bending process of the first lead frame 20and the second lead frame 30.

In addition, deflections of the first lead frame 20 and the second leadframe 30 are reduced by forming the first lead frame 20 and the secondlead frame 30 to be thick. Therefore, the light emitting device 10 canbe easily mounted.

On the contrary, if the first lead frame 20 and the second lead frame 30are formed in a thin flat plate, the bending process becomes easy, andthe lead frames 20, 30 can be formed in predetermined shapes.

The first lead frame 20 and the second lead frame 30 form a pair ofpositive and negative electrodes. It is sufficient if there is at leastone first lead frame 20 and at least one second lead frame 30,respectively. However, a plurality of the first lead frames and thesecond lead frames may be formed. In addition, if a plurality of thelight emitting devices 10 are mounted on the first lead frame 20, it isrequired to dispose a plurality of second lead frames 30.

<Second Resin Molding Body>

The second resin molding body 50 is formed for protecting the lightemitting device 10 from, for example, an external force, dusts, andmoisture of the external environment to effectively emit a lightoutside, which is emitted from the light emitting device 10. The secondresin molding body 50 is formed inside the concave portion 40 c of thefirst resin molding body 40.

Silicone resin or modified silicone resin is used for forming the secondresin molding body 50 in the embodiment.

It is noted that a thermosetting resin used for the second resin moldingbody 50 is not limited to the silicone resin or the modified siliconeresin.

In this case, it is preferable that the second resin molding body 50 isformed by at least one thermosetting resin selected from a group ofepoxy resin, modified epoxy resin, silicone resin, modified siliconeresin, acrylate resin, and urethane resin. Especially, the epoxy resin,modified epoxy resin, silicone resin, and modified silicone resin arepreferable. It is preferable that a hard resin is used for the secondresin molding body 50 for protecting the light emitting device 10.

In addition, it is preferable that a resin which is excellent in heatresistance, weather resistance, and light resistance is used for thesecond resin molding body 50. The second resin molding body 50 may bemixed with at least one selected from a group of a filler, lightdiffusion agent, fluorescent material, and reflective material forgiving a predetermined optical function. The second resin molding body50 may be mixed with the light diffusion agent.

As the specific light diffusion agents, barium titanate, titanium oxide,alumina, and silicon oxide preferably may be used. In addition, thesecond resin molding body 50 may contain an organic or inorganic colordye or color pigment for cutting light waves except for desired lightwaves. In addition, the second resin molding body 50 may contain afluorescent material 80 which absorbs a light emitted from the lightemitting device 10 and transforms wavelengths of the light into otherwavelengths.

(Fluorescent Material)

The fluorescent material 80 may be usable as long as the fluorescentmaterial 80 absorbs a light emitted from the light emitting device 10and transforms wavelengths of the light into different wavelengths. Forexample, it is preferable that the fluorescent material 80 is at leastone selected from a group of, for example, nitride fluorescentmaterials, oxynitride fluorescent materials, and sialon fluorescentmaterials, all of which are activated mainly by lanthanoid elements suchas Eu and Ce, alkaline earth halogen apatite fluorescent materials,alkaline earth metal boric-acid halogen fluorescent materials, alkalineearth metal aluminate fluorescent materials, alkaline earth silicates,alkaline earth sulfides, alkaline earth thiogallates, alkaline earthsilicon nitrides, and germinates, all of which are activated mainly byan element of lanthanoid elements such as Eu and transition metals suchas Mn, rare earth aluminate fluorescent materials and rare earthsilicates, all of which are activated mainly by an element of lanthanoidelements such as Ce, and organic or inorganic complexes which areactivated mainly by lanthanoid elements such as Eu. However, thefluorescent materials are not limited to those described above.

As the nitride fluorescent materials activated mainly by lanthanoidelements such as Eu and Ce, there exist, for example, M₂Si₅N₈:Eu andCaAlSiN₃:Eu (M is at least one selected from a group of Sr, Ca, Ba, Mg,and Zn). In addition, there exist, for example, MSi₇N₁₀:Eu,M_(1.8)Si₅O_(0.2)N₈:Eu, and M_(0.9)Si₇O_(0.1)N₁₀:Eu (M is at least oneselected from a group of Sr, Ca, Ba, Mg, and Zn).

As the oxynitride fluorescent materials activated mainly by lanthanoidelements such as Eu and Ce, there exists, for example, MSi₂O₂N₂:Eu (M isat least one selected from a group of Sr, Ca, Ba, Mg, and Zn).

As the sialon fluorescent materials activated mainly by lanthanoidelements such as Eu and Ce, there exists, for example,M_(p/)2Si_(12−p−q)Al_(p+q)O_(q)N_(16−p):Ce, which is composed ofM-Al—Si—O—N (M is at least one selected from a group of Sr, Ca, Ba, Mg,and Zn, q:0 to 2.5, p:1.5 to 3).

As the alkaline earth halogen apatite fluorescent materials activatedmainly by an element of lanthanoid elements such as Eu and transitionmetals such as Mn, there exists, for example, M₅(PO₄)₃X:R (M is at leastone selected from a group of Sr, Ca, Ba, Mg, and Zn. X is at least oneselected from a group of F, Cl, Br, and I. R is at least one selectedfrom a group of Eu, Mn, and Eu+Mn.)

As the alkaline earth metal boric-acid halogen fluorescent materials,there exists, for example, M₂B₅O₉X:R (M is at least one selected from agroup of Sr, Ca, Ba, Mg, and Zn. X is at least one selected from a groupof F, Cl, Br, and I. R is at least one selected from a group of Eu, Mn,and Eu+Mn.).

As the alkaline earth metal aluminate fluorescent materials, thereexist, for example, SrAl₂O₄:R, Sr₄Al₁₄O₂₅:R, CaAl₂O₄:R, BaMg₂Al₁₆O₂₇:R,BaMg₂Al₁₆O₁₂:R, and BaMgAl₁₀O₁₇:R(R is at least one selected from agroup of Eu, Mn, and Eu+Mn.).

As the alkaline earth sulfide fluorescent materials, there exist, forexample, La₂O₂S:Eu, Y₂O₂S:Eu, and Gd₂O₂S:Eu.

As the rare earth aluminate fluorescent materials which are activatedmainly by an element of lanthanoid elements such as Ce, there exist, forexample, YAG fluorescent materials which are expressed with thefollowing compositional formula Y₃Al₅O₁₂:Ce,(YO_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce, Y₃(Al_(0.8)Ga_(0.2))₅O₁₂:Ce, and (Y,Gd)₃(Al, Ga)₅O₁₂. In addition, there exist, for example, Tb₃Al₅O₁₂:Ceand Lu₃Al₅O₁₂:Ce, in which a part or all of Y in the YAG fluorescentmaterials are substituted by, for example, Tb or Lu.

Other than the fluorescent materials described above, there exist, forexample, ZnS:Eu, Zn₂GeO₄:Mn, and MGa₂S₄:Eu (M is at least one selectedfrom a group of Sr, Ca, Ba, Mg, and Zn. X is at least one selected froma group of F, Cl, Br, and I.)

The above fluorescent materials may contain at least one selected from agroup of Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti instead of Eu or inaddition to Eu as needed.

In addition, a fluorescent material 80 other than those described abovecan be used as long as the fluorescent material 80 has an identicalperformance and effect to those described above.

A fluorescent material 80 which emits, for example, yellow, red, green,or blue by an excitation light of the light emitting device 10 may beused. In addition, a fluorescent material 80 which emits, for example,yellow-green, blue-green, or orange color, which is an additive color ofthe above colors, may also be used. By combining these fluorescentmaterials, a side-view type light emitting apparatus which has variouskinds of emission spectra can be fabricated.

For example, the fluorescent material Y₃Al₅O₁₂:Ce or(Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce is irradiated with a blue light emitted fromGaN compound semiconductors to transform wavelengths of the blue light.As a result, a side-view type light emitting apparatus which emits awhite light, which is a mixed color between the blue light emitted fromthe light emitting device 10 and a light emitted from the fluorescentmaterial 80, can be provided.

For example, by using a fluorescent material CaSi₂O₂N₂:Eu orSrSi₂O₂N₂:Eu which emits a green to yellow light, (Sr, Ca)₅(PO₄)₃Cl:Euwhich emits a blue light, and (Ca, Sr)₂Si₅N₈:Eu which emits a red light,a side-view type light emitting apparatus which emits a white lighthaving an excellent color rendering properties can be provided. In thiscase, since red, blue, and green, that is, three primary colors areused, a desired white light can be obtained by changing compoundingratios among the CaSi₂O₂N₂:Eu or SrSi₂O₂N₂:Eu, (Sr, Ca)₅(PO₄)₃Cl:Eu, and(Ca, Sr)₂Si₅N₈:Eu.

<Fabrication Method of Side-View Type Light Emitting Apparatus>

A fabrication method of a side-view type light emitting apparatusaccording to the present invention will be explained. The fabricationmethod is used for the side-view type light emitting apparatus describedabove. FIG. 2A to FIG. 2E are brief cross sectional views showing afabrication process of a side-view type light emitting apparatusaccording to a first embodiment.

First, the first inner lead portion 20 a and the second inner leadportion 30 a corresponding to the bottom face 40 a of the concaveportion 40 c of the first resin molding body 40, and the first outerlead portion 20 b and the second outer lead portion 30 b are sandwichedby an upper die 120 and a lower die 121 (first process: see FIG. 2A,FIG. 2B).

The upper die 120 has a convex portion corresponding to a concaveportion of the first resin molding body. A portion of the upper die 120corresponding to the bottom face 40 a of the concave portion 40 c of thefirst resin molding body 40 is formed to come in contact with the firstinner lead portion 20 a and the second inner lead portion 30 a.

Next, a thermosetting resin is injected into a space formed between theupper die 120 and the lower die 121 by a transfer molding process from agate 30 disposed on a side face of the first resin molding body 40adjacent to a side face of the concave portion 40 c (second process: seeFIG. 2C).

The transfer molding process includes a series of the following steps. Athermosetting resin having a pellet shape with a predetermined size isput in a predetermined container, and pressed to inject the meltedthermosetting resin into a concave portion, which is communicated withthe container, between the upper die 120 and the lower die 121. Theupper die 120 and the lower die 121 are heated up at a predeterminedtemperature to harden the thermosetting resin injected into the concaveportion.

In the transfer molding process, since the first inner lead portion 20 aand the second inner lead portion 30 a are sandwiched by the upper die120 and lower die 121, a flip-flop of the first inner lead portion 20 aand the second inner lead portion 30 a and a generation of burrs can besuppressed when the thermosetting resin is injected.

In addition, since a correct position of the gate 130 is selected in thetransfer molding process, the thermosetting resin flows and spreads evenin an extremely thin portion, whose width is not more than 0.2 mm andpreferably not more than 0.1 mm, between a periphery of the concaveportion 40 c and the upper face side or lower face side of the firstresin molding body 40 on the light emitting surface 2. Accordingly, astable and uniform first resin molding body 40 can be provided.

The injected thermosetting resin is heated up and hardened to form apackage which is excellent in, for example, heat resistance, lightresistance, and adhesiveness, including the first resin molding body 40(third process: see FIG. 2C).

In the next process, the upper die 120 and the lower die 121 arereleased from the resin for mounting the light emitting device 10. If ahardening of the resin is not sufficient, the hardening process iscontinued so that the resin has a mechanical strength not to cause anyproblem in the later working process of the first resin molding body 40.

Next, the light emitting device 10 is mounted on the first inner leadportion 20 a. The light emitting device 10 has the first electrode 11and the second electrode 12. The first electrode 11 is electricallyconnected to the first inner lead portion 20 a and the second electrode12 is electrically connected to the second inner lead portion 30 a(fourth process: see FIG. 2D).

The first electrode 11 is electrically connected to the first inner leadportion 20 a through the wire 60 and the second electrode 12 iselectrically connected to the second inner lead portion 30 a through thewire 60.

In the next process, a thermosetting resin is filled in the concaveportion 40 c where the light emitting device 10 is mounted (fifthprocess: see FIG. 2E).

A dropping means, injection means, or extrusion means may be used forfilling the thermosetting resin. However, the dropping means ispreferable because a filling method using the dropping means caneffectively remove an air remaining in the concave portion 40 c. It ispreferable that the thermosetting resin is mixed with the fluorescentmaterial 80 because a color tone adjustment of the side-view type lightemitting apparatus can be easily implemented by the mixing of thefluorescent material 80.

In the last process, the thermosetting resin is heated up to be hardenedto form the second resin molding body 50 (sixth process: see FIG. 2E).

With the processes described above, the side-view type light emittingapparatus can be easily fabricated. In addition, the side-view typelight emitting apparatus having a high adhesiveness can be provided byforming the first resin molding body 40 and the second resin moldingbody 50 using the thermosetting resin.

In addition, the side-view type light emitting apparatus which isexcellent in, for example, heat resistance, light resistance, andadhesiveness can be provided, because a peeling off at an interfacebetween the first resin molding body 40 and the second resin moldingbody 50 does not occur.

1. A surface mount lateral light emitting apparatus, comprising: a lightemitting device; a first lead frame to be electrically connected to thelight emitting device; a second lead frame to be electrically connectedto the light emitting device; a first resin molding body in which aconcave portion for mounting the light emitting device is formed and thefirst lead frame and the second lead frame are fixed; and a second resinmolding body which covers the light emitting device to form a lightemitting surface in the concave portion of the first resin molding body,wherein the first resin molding body contains a filler or a lightdiffusion agent; wherein in a periphery of the concave portion, which isa periphery of the light emitting surface, a width of a straight portionof at least one side of the first resin molding body is not more than0.2 mm; and wherein the first resin molding body and the second resinmolding body are formed with a thermosetting resin.
 2. The surface mountlateral light emitting apparatus according to claim 1, wherein thethermosetting resin is an epoxy resin containing a triazine derivativeepoxy resin.
 3. The surface mount lateral light emitting apparatusaccording to claim 1, wherein the first resin molding body is formed bytransfer molding.
 4. A fabrication method of a surface mount laterallight emitting apparatus comprising a light emitting device; a firstlead frame to be electrically connected to the light emitting device; asecond lead frame to be electrically connected to the light emittingdevice; a first resin molding body in which a concave portion formounting the light emitting device is formed and the first lead frameand the second lead frame are fixed; and a second resin molding bodywhich covers the light emitting device to form a light emitting surfacein the concave portion of the first resin molding body, the fabricationmethod comprising steps of: a first step for sandwiching the first leadframe and the second lead frame by an upper die having a convex portioncorresponding to the concave portion of the first resin molding body anda lower die to be used in pairs together with the upper die; a secondstep for injecting a thermosetting resin containing a filler or a lightdiffusion agent into a space between the upper die and the lower diewhen the upper die is engaged with the lower die from a gate disposed ona side face of the first resin molding body adjacent to a side face ofthe concave portion of the first resin molding body; a third step forheating up the injected thermosetting resin to mold the first resinmolding body; a fourth step for mounting the light emitting device onthe first lead frame under the condition that at least the upper die isreleased from the injected thermosetting resin, and for electricallyconnecting a first electrode of the light emitting device to the firstlead frame and a second electrode of the light emitting device to thesecond lead frame; a fifth step for filling the thermosetting resin inthe concave portion where the light emitting device is mounted; and asixth step for heating up the filled thermosetting resin to mold thesecond resin molding body.